Wachovia Corp., the nation’s fourth-largest bank, said Wednesday that it would extend $150 billion in loan commitments to Californians over the next 10 years as part of its purchase of Golden West Financial Corp. of Oakland.

In May, Wachovia announced it would buy Golden West for more than $25.5 billion, making a big push into the West Coast and mortgage banking.

The plan does not represent an outright investment by Wachovia, but rather the amount of loans it expects to extend to consumers in California, some of them low-income.

The plan includes an estimated $70 billion in affordable mortgages and $60 billion in consumer loans to low and moderate-income consumers. The bank expects to sign $15 billion of small business loans and $4 billion in multi-family housing and community development loans.

Banks often announce their loan commitments to low-income neighborhoods as part of an attempt to smooth the regulatory process when they purchase another bank. Under the Community Reinvestment Act of 1977, banks are required to meet the needs of low and moderate-income neighborhoods, an area that regulators take into effect when approving a bank merger.